Oleaginous Seeds Research Articles

Crop seed oil bodies: From challenges in protein identification to an emerging picture of the oil body proteome

Oleaginous seeds store lipids in specialized structures called oil bodies (OBs). These organelles consist of a core of neutral lipids bound by proteins embedded in a phospholipid monolayer. OB proteins are well conserved in plants and have long been grouped into only two categories: structural proteins or enzymes. Recent work, however, which identified other classes of proteins associated with OBs, clearly shows that this classification is obsolete. Proteomics-mediated OB protein identification is facilitated in plants for which the genome is sequenced and annotated. However, it is not clear whether this knowledge can be dependably transposed to less well-characterized plants, including the well-established commercial sources of seed oil as well as the many others being proposed as novel sources for biodiesel, especially in Africa and Asia. Toward an update of the current data available on OB proteins this review discusses (i) the specific difficulties for proteomic studies of organelles; (ii) a 2012 census of the proteins found in seed OBs from various crops; (iii) the oleosin composition of OBs and their role in organelle stability; (iv) PTM of OB proteins as an emerging field of investigation; and finally we describe the emerging model of the OB proteome from oilseed crops.

Oil bodies: An insight on their microstructure — maize germ vs sunflower seed

Storage triacylglycerols in oleaginous seeds are surrounded by a layer that consists of phospholipids and proteins, mainly oleosins. These entities are intracellular organelles, known as oil bodies. It is often reported that they have a spherical shape, but imaging using cryo-SEM analysis showed that they are rather elastic and their shape depends on their surrounding environment. In this research we have shown that in maize germ, which has a relatively low moisture content, the oil body geometry depends on the available space they have. On the other hand, oil bodies in sunflower seeds, which contain double amounts of water, appear with an almost spherical shape. Oil bodies can be extracted from oleaginous seeds using an aqueous alkaline extraction, which leads to a stable natural oil-in-water emulsion. As no additional energy is required, this method can be considered as sustainable and may find a lot of potential uses in industry. Extraneous co-extracted proteins most likely form a second layer around the oil body surface, which protects the oil bodies from coalescence, even at high oil concentration. The extraneous proteins of maize germ oil body emulsions could be removed by applying aqueous washing steps, but not in the case of sunflower seed oil bodies.

Proximate Composition and Fatty Acids Profile in Oleaginous Seeds

Fatty acids were quantified in oleaginous seeds: pistachio, almonds, European nuts, cashew nuts, hazelnuts, Brazil nuts, pecan nuts, and macadamia nuts. Three brands of each sample were purchased in three lots (n = 9). The proximate composition, energetic value, and fatty acids (FA) were determined by gas chromatography. All seeds had large amounts of total lipids and the highest contents (ca. 70%) were found in macadamia, pecan, and European nuts. The samples had significant amounts of crude protein. Pistachio and cashew nuts had the greatest amount (ca. 20%), as well as the largest carbohydrate contents (32%). All seeds were rather energetic, ranging from 600 to 760 Kcal.g<sup>-1</sup>. From seven to nine FA were identified and quantified, oleic (n-9) and linoleic (n-6) acids were the major acids. Essential fatty acid a-linolenic (n-3) was found in European nuts (except pistachio) with an n-6/n-3 ratio (4:1) that is very beneficial to health. <em>Trans</em> FA were also observed in salted roasted cashew nuts. The major saturated FA (SFA) was palmitic, stearic, and arachidonic acids, however, their amounts were much lower than those of polyunsaturated acids (PUFA) and monounsaturated acids (MUFA). European nuts had the greatest PUFA/SFA ratio (9), followed by almonds (3.6).

Physiological quality of physic nut (Jatropha curcas L.) seeds during storage

The physic nut has been considered as one of the oilseed plants species with the highest potential for biofuel production. Oleaginous seeds demand special care during storage to maintain their quality. This study aimed to establish the most adequate conditions for their storage. Freshly-harvested seeds were dried until 7.2 moisture content and stored along a year, under the following conditions: environmental laboratory and cold chamber ( ±5 ºC and 60% RH), into paper bag, polypropylene bag, and cardboard barrel. Physiological quality was then assessed by the tests: germination; first count; germination speed index; seedling length; accelerated aging; cold test; field emergence; and emergence speed index, after zero, three, six, nine, and 12 months. There was linear reduction of germination and vigor of the seeds after storage under environmental laboratory condition, into paper or polypropylene bags, and cardboard barrel. Physiological quality was higher after storage in cold chamber, into paper or polypropylene bags; and into cardboard barrel, at environmental laboratory condition.

Natural Variation in Seed Very Long Chain Fatty Acid Content Is Controlled by a New Isoform of KCS18 in Arabidopsis thaliana

Oil from oleaginous seeds is mainly composed of triacylglycerols. Very long chain fatty acids (VLCFAs) are major constituents of triacylglycerols in many seed oils and represent valuable feedstock for industrial purposes. To identify genetic factors governing natural variability in VLCFA biosynthesis, a quantitative trait loci (QTL) analysis using a recombinant inbred line population derived from a cross between accessions Bay-0 and Shahdara was performed in Arabidopsis thaliana. Two fatty acid chain length ratio (CLR) QTL were identified, with one major locus, CLR.2, accounting for 77% of the observed phenotypic variation. A fine mapping and candidate gene approach showed that a key enzyme of the fatty acid elongation pathway, the β-ketoacyl-CoA synthase 18 (KCS18), was responsible for the CLR.2 QTL detected between Bay-0 and Shahdara. Association genetics and heterologous expression in yeast cells identified a single point mutation associated with an alteration of KCS18 activity, uncovering the molecular bases for the modulation of VLCFA content in these two natural populations of Arabidopsis. Identification of this kcs18 mutant with altered activity opens new perspectives for the modulation of oil composition in crop plants.

Mechanical Continuous Oil Expression from Oilseeds: A Review

The oil extraction by mechanical pressing is the most common method for continuous treatment of oleaginous seeds without solvent. Different types of presses can be used depending on the purpose (expeller, expander, and twin-screw extruder) and on the capacity range (3 kg h−1 to 150 t day−1). At the laboratory scale, many authors have highlighted the effect of operating parameters (screw rotation speed, temperature, and back pressure) and raw material (seed species, variety, water content, and pre-treatment) on process performance (oil yield and press capacity). For a given species, the main factors influencing the process are the pressure, temperature, and moisture content. The design of models mathematically describing the operation of continuous press allows to predict the behavior and performance of various presses.

Characterization and authentication of a novel vegetable source of omega-3 fatty acids, sacha inchi (Plukenetia volubilis L.) oil

Consumption of omega-3 fatty acids (ω-3's), whether from fish oils, flax or supplements, can protect against cardiovascular disease. Finding plant-based sources of the essential ω-3's could provide a sustainable, renewable and inexpensive source of ω-3's, compared to fish oils. Our objective was to develop a rapid test to characterize and detect adulteration in sacha inchi oils, a Peruvian seed containing higher levels of ω-3's in comparison to other oleaginous seeds. A temperature-controlled ZnSe ATR mid-infrared benchtop and diamond ATR mid-infrared portable handheld spectrometers were used to characterize sacha inchi oil and evaluate its oxidative stability compared to commercial oils. A soft independent model of class analogy (SIMCA) and partial least squares regression (PLSR) analyzed the spectral data. Fatty acid profiles showed that sacha inchi oil (44% linolenic acid) had levels of PUFA similar to those of flax oils. PLSR showed good correlation coefficients (R(2)>0.9) between reference tests and spectra from infrared devices, allowing for rapid determination of fatty acid composition and prediction of oxidative stability. Oils formed distinct clusters, allowing the evaluation of commercial sacha inchi oils from Peruvian markets and showed some prevalence of adulteration. Determining oil adulteration and quality parameters, by using the ATR-MIR portable handheld spectrometer, allowed for portability and ease-of-use, making it a great alternative to traditional testing methods.

A novel method for extraction of oils from oleaginous seeds

A new method of extraction of oils from oleaginous seeds was developed. This method is based on the use of aqueous solution of polyethylene glycol sorbitan monolaurate (Tween 20). Compared with existing methods, the new technique is rapid and enviroµmentally friendly. In addition, the obtained oil by this method has the same physicochemical properties and similar composition as those obtained by the classical method with a better antioxidant potential revealed by DPPH test.

Archaeobotanical research at the medieval fortified site of Îgîlîz (Anti-Atlas, Morocco) with particular reference to the exploitation of the argan tree

The analysis of botanical macro-remains (seeds, fruits and wood) from the fortress site of Igiliz, situated in the Anti-Atlas mountain range of southern Morocco, provides a first glimpse of the plant economy of a medieval rural community in this part of North Africa. Considered as the original stronghold of the religious community led by Ibn Tumart, the founder of the Almohad dynasty, the site was occupied from the 10th to the 13th century a.d. The crop assemblage identified from ashy contexts in a central grouping of buildings (the qasba) comprises barley (Hordeum vulgare), sorghum (Sorghum sp., earliest occurrence known so far from Morocco), wheat (Triticum sp.) and a pulse (Lathyrus sativus/cicera). Several arboreal fruit species are also identified: fig (Ficus carica), almond (Prunus dulcis), date palm (Phoenix dactylifera), grapevine (Vitis vinifera) and argan (Argania spinosa). The latter, predominant in the archaeobotanical record in the form of both fruit and wood remains, is of particular interest as it is the first time that this species, endemic to south-western Morocco and of prime economic interest regionally, has been identified from an archaeological context. In the past, as today, the argan tree seems to have played a major role in village economies as a source of wood for fuel and construction, fodder for livestock and food in the form of an edible oil, extracted from the oleaginous seeds. This article focuses on present and past uses of Argania spinosa as well as on the ecology and morpho-anatomy of this emblematic species.

Experimental and modelling of supercritical oil extraction from rapeseeds and sunflower seeds

The supercritical oil extraction from oleaginous seeds (sunflower and rapeseeds) is presented here through experimental and modelling results. The experimental setup allows an accurate following of the mass of the oil extracted and to derive the experimental influences of pressure, temperature and supercritical CO 2 flowrate on the extraction curves. These parameters are very sensitive and highlight the necessity of precise optimisation of experimental conditions. In order to complete the behaviour of supercritical fluids extraction, an improved modelling is proposed. The modelling basic equations are based on others modelling published previously. In this work, the determination of several parameters comes from correlations and the other constants are fitted with all the experimental results. Thus the modelling is more representative and predictive as other ones. The modelling results present a good agreement with the experimental results, and hence it can be used for the dimensioning of some extraction autoclaves.

Teste de condutividade elétrica na avaliação de sementes de girassol armazenadas sob diferentes temperaturas

A deterioração é um dos grandes problemas do armazenamento de sementes, principalmente das oleaginosas. Estudos recentes têm evidenciado que a eficiência do teste de condutividade elétrica pode ser influenciada pela temperatura de armazenamento das sementes. Este fato sugere que a deterioração da semente, principalmente em baixas temperaturas de armazenamento, pode não estar relacionada diretamente com a perda da integridade das membranas celulares. Para investigar o efeito de diferentes temperaturas de armazenamento sobre os resultados do teste de condutividade elétrica em sementes de girassol (Helianthus annuus L.), sementes dos híbridos Helio 250 e Helio 251 foram embaladas em papel Kraft multifoliado e armazenadas nas temperaturas: 10 e 25 °C (constante) e 25 °C por seis meses e depois transferidas para 10 ºC até o final do período de armazenamento, sendo que a cada três meses, num total de doze meses, a qualidade fisiológica das sementes foi avaliada pelos testes de germinação, emergência de plântulas, envelhecimento acelerado, condutividade elétrica. Também foi determinado o teor de água das sementes. O teste de condutividade elétrica não é eficiente na detecção do processo de deterioração em sementes de girassol armazenadas sob baixa temperatura.

Valorization of Some By-Products of Maltese Orange from Tunisia: Peel Essential Oil and Seeds Oil

Oranges are mainly used for juice extraction. This industry provides by-products which aren’t used and have to be valorised. The aim of this work was to analyse the composition of peel essential oil of Maltese or blood orange of Tunisia and to ascertain also the fatty acids (FA) composition of its seeds oil. The results showed that the main by-product of blood orange was pulp (58.6 %) followed by peel (41.1 %) and seeds (2 %). We noted the prevalence of monoterpenes such as limonene, 3-carene and phellandrene in blood orange peel essential oil. Furthermore, blood orange seeds were characterized by a considerable oil yield (17.3 %) similar to that of oleaginous seeds. Blood orange seeds oil was classified as a linoleic oil since it was characterized by the predominance of the linoleic acid (C 18: 2) accounting for 39.7 % of the total fatty acids (TFA).

Olive oil adulterated with hazelnut oils: simulation to identify possible risks to allergic consumers

According to European Union Regulation EC 1531/2001, olive oil labelled as “extra-virgin” should be cold-pressed and contain no refined oil or oil from other oleaginous seeds or nuts. Adulteration of extra virgin olive oil (EVOO) with hazelnut oil (HAO) is a serious concern both for oil suppliers and consumers. The high degree of similarity between the two fats complicates the detection of low percentages of HAO in EVOO. Many analytical approaches have been developed in recent years to trace HAO in EVOO, principally based on chromatographic analyses, differential scanning calorimetry or nuclear magnetic resonance. In addition adulteration of EVOO with HAO may introduce hazelnut-derived allergens. The aim of this work was to analyse the protein and allergen content of EVOO intentionally spiked with raw cold-pressed HAO or solvent-extracted HAO. SDS–PAGE analysis confirmed the presence of hazelnut proteins in solvent-extracted HAO with molecular masses ranging 10–60 kDa. In contrast, cold-pressed HAO showed no traces of protein. In spiked EVOO, solvent-extracted HAO was still detectable at a 1% contamination level. Several bands on SDS–PAGE migrated at apparent molecular masses coinciding with known allergens, such as Cor a 1 (∼17 kDa), Cor a 2 (∼14 kDa), Cor a 8 (∼12 kDa), oleosin (∼17 kDa) and Cor a 9 (∼60 kDa). MALDI–TOF MS analysis confirmed the presence of two oleosin isoforms and of Cor a 9. Immunoblotting demonstrated that an allergic patient with known reactivity to Cor a 1 and Cor a 2 recognized a 17-kDa band in solvent-extracted HAO. In conclusion, we have shown that adulteration of extra virgin olive oil with solvent-extracted hazelnut oil can be traced by simple SDS–PAGE analysis, and that adulteration introduces a potential risk for hazelnut allergic patients.

High tocopherol and triacylglycerol contents in Pinuspinea L. seeds

Oleaginous seeds are among the functional foods most recognized for their tocopherols and triacylglycerols because of their role in lipid metabolism. In this paper, the tocopherol and triacylglycerol contents in seeds of several Pinus pinea L. populations around the Mediterranean Basin were investigated. Lipids were extracted from fully ripen seeds with petroleum ether. The tocopherol (α-tocopherol, γ-tocopherol, and δ-tocopherol) contents were, respectively, 15.34±3.75 ppm, 1,681.75±404.03 ppm and 41.87±9.79 ppm. Lipids (mainly triacylglycerols) in P. pinea seeds averaged 48% on a dry weight basis. Triacylglycerols with an equivalent carbon number of 44 (32.27%) and of 46 (30.91%) were dominant. The major triacylglycerol was LLO (24.06%). Tocopherols and triacylglycerols were present at remarkably high levels, thus making P. pinea oil a valuable source of antioxidants and unsaturated fatty acids with varying levels across the geographical range of P. pinea.

Extraction from oleaginous seeds using supercritical CO 2: Experimental design and products quality

An experimental design has been built in order to study the influence of different parameters on the oil extraction yield for two types of seeds (rape and sunflower) using supercritical CO 2: pressure (15–45 MPa), temperature (35–75 °C), CO 2 flow rate (8–19 kg h −1) and extraction duration (20–120 min). Extraction yields are between 0.3% and 89.8%, indicating that the experimental design covers a large range of results. Acidic and phosphorus contents in the oil and protein content in the residual cake have been done. The results indicate that pressure and extraction duration are the most influencing parameters together with temperature in the case of rape seeds. Thermodynamic effects (solubility) and kinetic effects (mass transfer depending on the seeds) have been evidenced. The selectivity of pure supercritical CO 2 has been shown: any phospholipid is extracted. In addition to selectivity, another interest of the process is the purity of the products recovered, totally free from organic solvent.

Microwave-integrated extraction of total fats and oils

An improved process of Soxhlet extraction assisted by microwave, called microwave-integrated Soxhlet (MIS) is proposed for the extraction of oils and fats from different food matrixes such as oleaginous seeds, meat and bakery products. Optimal conditions for extraction were obtained using a response surface methodology and reached from a central composite design allowing us to conclude in a previous paper that the proposed process ensures complete, efficient and accurate extraction for lipids determination from olives. In this paper, the peak areas of the main fatty acids extracted with MIS from olive seeds were considered as response variables and submitted to an analysis of variance in order to determine if there was a significant link between the extraction of fatty acids and the variables required in extraction procedures. Results have shown that MIS parameters do not affect the composition of the extracts. For the generalization of the study with several food matrixes, MIS extraction results obtained were then compared to conventional Soxhlet extraction in terms of crude extract and fatty acid composition and shown that the oils extracted by MIS were quantitatively and qualitatively similar to those obtained by conventional Soxhlet extraction. MIS labstation can be considered as a new and general alternative for the extraction of lipids by using microwave energy.

Green procedure with a green solvent for fats and oils’ determination: Microwave-integrated Soxhlet using limonene followed by microwave Clevenger distillation

Here is described a green and original alternative procedure for fats and oils’ determination in oleaginous seeds. Extractions were carried out using a by-product of the citrus industry as extraction solvent, namely d-limonene, instead of hazardous petroleum solvents such as n-hexane. The described method is achieved in two steps using microwave energy: at first, extractions are attained using microwave-integrated Soxhlet, followed by the elimination of the solvent from the medium using a microwave Clevenger distillation in the second step. Oils extracted from olive seeds were compared with both conventional Soxhlet and microwave-integrated Soxhlet extraction procedures performed with n-hexane in terms of qualitative and quantitative determination. No significant difference was obtained between each extract allowing us to conclude that the proposed method is effective and valuable.

Oleaginous seeds, press-cake and seed husks for the biosorption of metals

The press-cake (PC) of oleaginous species (Brassica napus, Moringa oleifera, Glycine max) has been investigated as a biosorbent for metals removal from contaminated water.

Selective One-Step Extraction of Arabidopsis thaliana Seed Oleosins Using Organic Solvents

Oleosins are hydrophobic proteins from oleaginous seeds, surrounding and stabilizing oil bodies. They are known to display interesting interfacial properties. Specific sera were raised against four different A. thaliana oleosins and used in dot-blot assays for oleosin quantification. These assays were used to set up extraction of oleosins from A. thaliana seeds. One mixture of chloroform/methanol gave optimal oleosin extraction. Extracted proteins represented 9% of seed proteins and were identified by immunoblot and proteomic analyses. Oleosins accounted for 79% of the extracted proteins. This simple one-step procedure allows selective extraction and concentration of oleosins from seeds without tedious oil body purification. Oleosin extract was indeed used to demonstrate the presence of the rare oleosin S5 in mature seeds. Moreover, this method will be useful to investigate the potential use of oleosins as emulsifier and to question their possible allergenicity.

Wastewater reclamation through a combination of natural systems (infiltration-percolation and constructed wetlands): a solution for small communities

The decision on technologies used for reclaiming wastewater appears as important as a consequence of the implications on the economic, environmental and health conditions of societies. The problem arises when deciding how to deal with wastewater in small communities, because the costs of implementing and operating small, intensive wastewater treatment plants are unacceptable and can lead to financing and operation problems. Extensive treatment systems can be a good solution, where space is available. This paper presents the combination of two soft technologies (infiltration-percolation and constructed wetlands) to treat and reclaim wastewater. The obtained results show that the infiltration-percolation effluent presents a quality enough to be reused for irrigation of industrial crops, nurseries, fodder, cereals and oleaginous seeds, ornamental flower production; industrial cooling; impoundments, water bodies, and streams for recreational use in which the public's contact with the water is not permitted; and irrigation of forested areas, landscape areas and restricted access areas. Moreover, the combination of infiltration-percolation and constructed wetlands increases the list of final reclamation to the following: irrigation of pasture for milk or meat animals, crops for canning industry, crops not raw-consumed, fruit trees except by sprinkling, aquaculture; and aquifer recharge by localised percolation through the soil.